<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html lang="en">
<head>
<title>Source code</title>
<link rel="stylesheet" type="text/css" href="../../../../../stylesheet.css" title="Style">
</head>
<body>
<div class="sourceContainer">
<pre><span class="sourceLineNo">001</span><a name="line.1"></a>
<span class="sourceLineNo">002</span>/*<a name="line.2"></a>
<span class="sourceLineNo">003</span> * Copyright (C) 2012 Archie L. Cobbs. All rights reserved.<a name="line.3"></a>
<span class="sourceLineNo">004</span> *<a name="line.4"></a>
<span class="sourceLineNo">005</span> * $Id: AbstractDelegate.html 740 2013-10-02 21:27:31Z archie.cobbs $<a name="line.5"></a>
<span class="sourceLineNo">006</span> */<a name="line.6"></a>
<span class="sourceLineNo">007</span><a name="line.7"></a>
<span class="sourceLineNo">008</span>package org.dellroad.stuff.pobj;<a name="line.8"></a>
<span class="sourceLineNo">009</span><a name="line.9"></a>
<span class="sourceLineNo">010</span>import java.io.IOException;<a name="line.10"></a>
<span class="sourceLineNo">011</span>import java.io.StringReader;<a name="line.11"></a>
<span class="sourceLineNo">012</span>import java.io.StringWriter;<a name="line.12"></a>
<span class="sourceLineNo">013</span>import java.util.Set;<a name="line.13"></a>
<span class="sourceLineNo">014</span><a name="line.14"></a>
<span class="sourceLineNo">015</span>import javax.validation.ConstraintViolation;<a name="line.15"></a>
<span class="sourceLineNo">016</span>import javax.xml.transform.stream.StreamResult;<a name="line.16"></a>
<span class="sourceLineNo">017</span>import javax.xml.transform.stream.StreamSource;<a name="line.17"></a>
<span class="sourceLineNo">018</span><a name="line.18"></a>
<span class="sourceLineNo">019</span>import org.dellroad.stuff.validation.ValidationContext;<a name="line.19"></a>
<span class="sourceLineNo">020</span>import org.slf4j.Logger;<a name="line.20"></a>
<span class="sourceLineNo">021</span>import org.slf4j.LoggerFactory;<a name="line.21"></a>
<span class="sourceLineNo">022</span><a name="line.22"></a>
<span class="sourceLineNo">023</span>/**<a name="line.23"></a>
<span class="sourceLineNo">024</span> * Support superclass for {@link PersistentObjectDelegate} classes, with implementations of all methods<a name="line.24"></a>
<span class="sourceLineNo">025</span> * other than {@link #serialize serialize()} and {@link #deserialize deserialize()}.<a name="line.25"></a>
<span class="sourceLineNo">026</span> *<a name="line.26"></a>
<span class="sourceLineNo">027</span> * @param &lt;T&gt; type of the root persistent object<a name="line.27"></a>
<span class="sourceLineNo">028</span> * @see PersistentObject<a name="line.28"></a>
<span class="sourceLineNo">029</span> */<a name="line.29"></a>
<span class="sourceLineNo">030</span>public abstract class AbstractDelegate&lt;T&gt; implements PersistentObjectDelegate&lt;T&gt; {<a name="line.30"></a>
<span class="sourceLineNo">031</span><a name="line.31"></a>
<span class="sourceLineNo">032</span>    private static final int BUFFER_SIZE = 16 * 1024 - 32;<a name="line.32"></a>
<span class="sourceLineNo">033</span><a name="line.33"></a>
<span class="sourceLineNo">034</span>    protected final Logger log = LoggerFactory.getLogger(this.getClass());<a name="line.34"></a>
<span class="sourceLineNo">035</span><a name="line.35"></a>
<span class="sourceLineNo">036</span>    /**<a name="line.36"></a>
<span class="sourceLineNo">037</span>     * Make a deep copy of the given object.<a name="line.37"></a>
<span class="sourceLineNo">038</span>     *<a name="line.38"></a>
<span class="sourceLineNo">039</span>     * &lt;p&gt;<a name="line.39"></a>
<span class="sourceLineNo">040</span>     * The implementation in {@link AbstractDelegate} does this by {@linkplain #serialize serializing}<a name="line.40"></a>
<span class="sourceLineNo">041</span>     * and then {@linkplain #deserialize deserializing} the object graph.<a name="line.41"></a>
<span class="sourceLineNo">042</span>     * Subclasses are encouraged to provide a more efficient implementation, for example, by implementing<a name="line.42"></a>
<span class="sourceLineNo">043</span>     * {@link org.dellroad.stuff.java.GraphCloneable}.<a name="line.43"></a>
<span class="sourceLineNo">044</span>     * &lt;/p&gt;<a name="line.44"></a>
<span class="sourceLineNo">045</span>     *<a name="line.45"></a>
<span class="sourceLineNo">046</span>     * @throws IllegalArgumentException if {@code original} is null<a name="line.46"></a>
<span class="sourceLineNo">047</span>     * @throws PersistentObjectException if an error occurs<a name="line.47"></a>
<span class="sourceLineNo">048</span>     */<a name="line.48"></a>
<span class="sourceLineNo">049</span>    public T copy(T original) {<a name="line.49"></a>
<span class="sourceLineNo">050</span>        if (original == null)<a name="line.50"></a>
<span class="sourceLineNo">051</span>            throw new IllegalArgumentException("null original");<a name="line.51"></a>
<span class="sourceLineNo">052</span>        StringWriter buffer = new StringWriter(BUFFER_SIZE);<a name="line.52"></a>
<span class="sourceLineNo">053</span>        try {<a name="line.53"></a>
<span class="sourceLineNo">054</span>            this.serialize(original, new StreamResult(buffer));<a name="line.54"></a>
<span class="sourceLineNo">055</span>        } catch (IOException e) {<a name="line.55"></a>
<span class="sourceLineNo">056</span>            throw new PersistentObjectException("exception during serialize()");<a name="line.56"></a>
<span class="sourceLineNo">057</span>        }<a name="line.57"></a>
<span class="sourceLineNo">058</span>        StreamSource source = new StreamSource(new StringReader(buffer.toString()));<a name="line.58"></a>
<span class="sourceLineNo">059</span>        T copy;<a name="line.59"></a>
<span class="sourceLineNo">060</span>        try {<a name="line.60"></a>
<span class="sourceLineNo">061</span>            copy = this.deserialize(source);<a name="line.61"></a>
<span class="sourceLineNo">062</span>        } catch (IOException e) {<a name="line.62"></a>
<span class="sourceLineNo">063</span>            throw new PersistentObjectException("exception during deserialize()");<a name="line.63"></a>
<span class="sourceLineNo">064</span>        }<a name="line.64"></a>
<span class="sourceLineNo">065</span>        if (copy == null)<a name="line.65"></a>
<span class="sourceLineNo">066</span>            throw new PersistentObjectException("null object returned by deserialize()");<a name="line.66"></a>
<span class="sourceLineNo">067</span>        return copy;<a name="line.67"></a>
<span class="sourceLineNo">068</span>    }<a name="line.68"></a>
<span class="sourceLineNo">069</span><a name="line.69"></a>
<span class="sourceLineNo">070</span>    /**<a name="line.70"></a>
<span class="sourceLineNo">071</span>     * Compare two object graphs.<a name="line.71"></a>
<span class="sourceLineNo">072</span>     *<a name="line.72"></a>
<span class="sourceLineNo">073</span>     * &lt;p&gt;<a name="line.73"></a>
<span class="sourceLineNo">074</span>     * The implementation in {@link AbstractDelegate} only returns true if {@code root1 == root2}.<a name="line.74"></a>
<span class="sourceLineNo">075</span>     * This is a very conservative implementation. If your root object graph correctly implements<a name="line.75"></a>
<span class="sourceLineNo">076</span>     * {@link Object#equals equals()}, then {@code root1.equals(root2)} would be a more appropriate test.<a name="line.76"></a>
<span class="sourceLineNo">077</span>     *<a name="line.77"></a>
<span class="sourceLineNo">078</span>     * @param root1 first object graph (never null)<a name="line.78"></a>
<span class="sourceLineNo">079</span>     * @param root2 second object graph (never null)<a name="line.79"></a>
<span class="sourceLineNo">080</span>     */<a name="line.80"></a>
<span class="sourceLineNo">081</span>    @Override<a name="line.81"></a>
<span class="sourceLineNo">082</span>    public boolean isSameGraph(T root1, T root2) {<a name="line.82"></a>
<span class="sourceLineNo">083</span>        return root1 == root2;<a name="line.83"></a>
<span class="sourceLineNo">084</span>    }<a name="line.84"></a>
<span class="sourceLineNo">085</span><a name="line.85"></a>
<span class="sourceLineNo">086</span>    /**<a name="line.86"></a>
<span class="sourceLineNo">087</span>     * Validate the given instance.<a name="line.87"></a>
<span class="sourceLineNo">088</span>     *<a name="line.88"></a>
<span class="sourceLineNo">089</span>     * &lt;p&gt;<a name="line.89"></a>
<span class="sourceLineNo">090</span>     * The implementation in {@link AbstractDelegate} performs validation using {@link ValidationContext#validate()}.<a name="line.90"></a>
<span class="sourceLineNo">091</span>     *<a name="line.91"></a>
<span class="sourceLineNo">092</span>     * @throws IllegalArgumentException if {@code obj} is null<a name="line.92"></a>
<span class="sourceLineNo">093</span>     * @return set of zero or more constraint violations<a name="line.93"></a>
<span class="sourceLineNo">094</span>     */<a name="line.94"></a>
<span class="sourceLineNo">095</span>    @Override<a name="line.95"></a>
<span class="sourceLineNo">096</span>    public Set&lt;ConstraintViolation&lt;T&gt;&gt; validate(T obj) {<a name="line.96"></a>
<span class="sourceLineNo">097</span>        return new ValidationContext&lt;T&gt;(obj).validate();<a name="line.97"></a>
<span class="sourceLineNo">098</span>    }<a name="line.98"></a>
<span class="sourceLineNo">099</span><a name="line.99"></a>
<span class="sourceLineNo">100</span>    /**<a name="line.100"></a>
<span class="sourceLineNo">101</span>     * Handle an exception thrown during a delayed write-back attempt. {@link ThreadDeath} exceptions are not<a name="line.101"></a>
<span class="sourceLineNo">102</span>     * passed to this method, but all others are.<a name="line.102"></a>
<span class="sourceLineNo">103</span>     *<a name="line.103"></a>
<span class="sourceLineNo">104</span>     * &lt;p&gt;<a name="line.104"></a>
<span class="sourceLineNo">105</span>     * The implementation in {@link AbstractDelegate} simply logs an error to {@link #log}.<a name="line.105"></a>
<span class="sourceLineNo">106</span>     *<a name="line.106"></a>
<span class="sourceLineNo">107</span>     * @param pobj the instance that encountered the exception<a name="line.107"></a>
<span class="sourceLineNo">108</span>     * @param t the exception thrown<a name="line.108"></a>
<span class="sourceLineNo">109</span>     */<a name="line.109"></a>
<span class="sourceLineNo">110</span>    @Override<a name="line.110"></a>
<span class="sourceLineNo">111</span>    public void handleWritebackException(PersistentObject&lt;T&gt; pobj, Throwable t) {<a name="line.111"></a>
<span class="sourceLineNo">112</span>        this.log.error(pobj + ": error during write-back", t);<a name="line.112"></a>
<span class="sourceLineNo">113</span>    }<a name="line.113"></a>
<span class="sourceLineNo">114</span><a name="line.114"></a>
<span class="sourceLineNo">115</span>    /**<a name="line.115"></a>
<span class="sourceLineNo">116</span>     * Get the default value for the root object graph. This method is invoked at startup when the persistent file does not exist.<a name="line.116"></a>
<span class="sourceLineNo">117</span>     * If this method returns null, then an {@linkplain PersistentObject#isAllowEmptyStart empty start} occurs unless the<a name="line.117"></a>
<span class="sourceLineNo">118</span>     * {@link PersistentObject} object is configured to disallow them, in which case an exception is thrown.<a name="line.118"></a>
<span class="sourceLineNo">119</span>     *<a name="line.119"></a>
<span class="sourceLineNo">120</span>     * &lt;p&gt;<a name="line.120"></a>
<span class="sourceLineNo">121</span>     * The implementation in {@link AbstractDelegate} returns null<a name="line.121"></a>
<span class="sourceLineNo">122</span>     *<a name="line.122"></a>
<span class="sourceLineNo">123</span>     * @return root object initial value, or null if there is no default value<a name="line.123"></a>
<span class="sourceLineNo">124</span>     */<a name="line.124"></a>
<span class="sourceLineNo">125</span>    @Override<a name="line.125"></a>
<span class="sourceLineNo">126</span>    public T getDefaultValue() {<a name="line.126"></a>
<span class="sourceLineNo">127</span>        return null;<a name="line.127"></a>
<span class="sourceLineNo">128</span>    }<a name="line.128"></a>
<span class="sourceLineNo">129</span>}<a name="line.129"></a>
<span class="sourceLineNo">130</span><a name="line.130"></a>




























































</pre>
</div>
</body>
</html>
